Gangly, big eared, with a shrill voice and a tendency to laugh before anyone else in the room, few presidents seem more unelectable than abraham lincoln. But his leadership in a time when red states and blue states were soaked in blood makes him one of our most beloved americans. A perfect character for a founding father of the blockbuster, steven spielberg, who sat down with his lincoln, daniel day lewis, and our diane sawyer. Reporter: Fascinated by lincoln since he was a child, steven spielberg always wanted to do this movie. America at its finest, with lincoln as the prism for understanding the delicate balance between dedication and doubt. I have this recollection from my childhood, when my uncle took me to the lincoln memorial and you're led into this dark, kind of rotunda, and there is a giant sitting in a chair. Reporter: What did you see in hi face? Do you remember? I thought he was looking directly at me. And that was it. Reporter: I'm trying to imagine the two of you as children. We still are. Reporter: Okay, makes it easier, it helps. The boy who grew up to be a director, carrying a dream. And knowing there was only one actor for this role. Did you hear anything about lincoln? Certainly was awar of him in some form or another from a fairly young age and I think it might have been from the cards that you got with bubble gum. Reporter: For nearly eight years, daniel day lewis, who grew up in england and ireland, said no. It would be impossible to embody america's most dearly loved president. Seemed like such an important thing. Last thing I wanted to do was to desecrate the memory of the most dearly loved president of this country, so -- it took some time. It took a lot of time and a lot of shyness around it. Yes. Reporter: But at a meeting last year, spielberg kept seeing lincoln in his face and, so, sneaked out his camera. You snapped a photo? Yeah. I didn't tell him I did that. When did you do that? Oh, a long time ago. You don't need to know about that. It was the first time that daniel, you know, was in a wonderful light, in a beautiful back light and I just went with my little -- like that, a hip shot. It was just right off the hip. Reporter: I love the idea of you at paparazzi. Exactly, exactly. Reporter: And then, there it was on the screen. Lincoln. Daunting, monumenully human. He was awkward to look at and his voice didn't fit his stature and he would just disarm a room with a crazy story that had no relevance to the issue of why they were in the room to begin with. Time is a great thickener of things. I suppose it is. Actually, I have no idea what i mean by that. If no one latches at the stories, he'd be the first one to guffaw at the story he'd be telling. Reporter: And the actor who grew up in another country found abraham lincoln's famous reedy voice. I never had a single conversation with daniel about the voice or the physicalization of lincoln. That was daniel's discovery process. One day, I got a little cassette tape in the mail from daniel. When I turned on the player, i heard the president speaking to me. I like our chances now. Reporter: And so they were ready to go with a brilliant screen play about noblest goals. And course politics. Before me stands stinking, demoral karras of the gentleman from ohio. Proof that some are inferior, endowed by their maker with dim wits. Reporter: Actor tommy lee jones plays the aging firebrand about lish nis, representatived that yus stevens. You are more reptile than man, george. So low and flat that the foot of man is incapable of crushing you. How dare you. Reporter: Inside the film, there are details from a time capsule. The kentucky historic society let them use the real sound of lincoln's real watch. When you hear that gentle ticking, that's the ticking that lincoln himself heard 150 years ago. Reporter: A man, forced to make wrenching decisions. And the reality of a father who had one child off at war, another lost to typhoid fever. His youngest, by his side. He adored tad. Tad was a complete anarchist and there were so many descriptions of the chaos that he caused in e white house. Please don't encourage him. Driving a goat cart up and down the quarters of the white house. You're back! Reporter: Exuberance. Absolutely. I think, yes, loved the force of life. I think in some way, tad represented the future, what tomorrow would bring. Reporter: And a different portrait of the wife by his side. Mrs. Lincoln. Madame president. Reporter: Mary lincoln, who had once been the girl every man courted, but chose this country lawyer because she saw something in him, perhaps before he did. She was standing on the precipice of herself. Never knowing which way she was going to fall with it, go right into the abyss. eporter: SALLY FIELD IN A Marriage at one searing and loving, warning her husband that he alone can and must end slavery and end the civil war. Because if you fail to acquire the necessary votes, woe unto you, you will answer to me. Reporter: And so, one very human man against the odds, against the opposition. Blood's been spilled to afford us this moment. Reporter: Creating one nation, with a vision of what we can be at our best. Shall we stop this bleeding?

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